The present invention relates to protocol testing, and more particularly to a method of determining configuration parameters of a mobile network from signaling information during network startup, which configuration parameters are periodically updated during network runtime.
The description below uses a UMTS (Universal Mobile Telecommunication System) network for illustrative purposes, but the invention may be applied to networks of other standards, notably mobile networks of future mobile communication standards. Further information on the terms used below in connection with the UMTS network may be obtained from documentation available via the domain www.3GPP.org: Document 3GPP (3rd Generation Partnership Project) TS (Technical Specification) 25.301 provides an overview of channel usage in the UMTS network. Documents 3GPP TS 25.427 and 3GPP TS 25.435 deal with frame protocol, document 3GPP TS 25.321 deals with MAC (Medium Access Control), document 3GPP TS 25.322 with RLC (Radio Link Control protocol), document 3GPP TS 25.331 with RRC (Radio Resource Control) and, finally, document 3GPP TS 25.433 with NBAP (Node B Appliccation Part). Further information on ALCAP (Access Link Control Application Part) may be obtained from ITU (International Telecommunications Union) Recommendation ITU Q.2630.2.
For a better understanding of the problem underlying the invention, FIG. 1 shows a part of the UMTS network with an MSC (Mobile Service switching Center) 10, three RNCs (Radio Network Controllers) 14A, 14B, 14C, three Node Bs 16A, 16B, 16C as well as three mobile units (user equipments—UE) 18A, 18B, 18C (mobile phones), with one or several user equipments being allocated to a cell. In the present example the user equipments 18B, 18C are allocated to cell 1 20A. Between the MSC 10 and each RNC 14 there is arranged one Iu interface each, between RNC 14B and each Node B 16A, 16B, 16C there is arranged one Iub interface each between RNCs 14A, 14B, 14C there is arranged one Iur interface each, and between mobile units 18A, 18B,18C and Node B 16B there is arranged one Uu interface each.
To further improve comprehensibility the Iub interface is examined. The functions of Node B are summarized as follows: it forms a logical node, such as the BTS (Base Transceiver Station) in a GSM (Global System for Mobile communication) network; it is responsible for the transmitting and receiving in one or a plurality of radio cells to/from user equipment; it terminates the Iub interface, i.e., the NBAP and the ALCAP; it is used for RF Radio Frequency) power control; and it operates a predeterminable number of radio cells. Node B thus is a base station to which there are connected a plurality of transmitter and receiver antennas, each such antenna combination defining a radio cell. RNC controls the use and the integrity of the radio resources; it terminates RANAP (Radio Access Network Application Protocol), NBAP, ALCAP, RNSAP (Radio Network Subsystem Application Part) and RRC/RLC(Radio Link Control)/MAC; and it forms the central element of the UMTS network. RNC thus is a radio switching station to which a plurality of radio base stations are connected.
The functions of the protocol used at the Iub interface are described as follows: start-up and maintenance of Node B; management of the Iub transport resources; management of the radio resources; measurements of the quality of the air interface; and measurements of the data volume and of the positions of mobile units. It furthermore controls the transfer of operation-relevant system information to the mobile units. Apart from that, the following functions are realised at the Iub interface: traffic management for common channels, i.e., for channels that are applicable to all subscribers connected to the relevant Node B, particularly access control systems; and control of the transmission capacity and data transfer. Moreover, it takes over the functions of traffic management for dedicated channels, i.e., channels allocated to a particular subscriber, notably radio link management, radio link supervision, channel allocation/deallocation, control of the transmission capacity and data transfer. If a real RNC is to be tested from the Iub interface, the network elements emanating from the respective Iub interface to the outside, i.e., the Node Bs, the cells and the user equipments or the network topology connected to an RNC in the direction of the network edge, have to be configured.
If one wants to monitor a high load or generate (by simulation) a high load for a test, the relevant units have to be subjected to loads that come as close as possible to their respective capacity limits. It is possible for an RNC to be allocated to approximately 1,000 Node Bs, each Node B may have up to 24 cells, and each cell in turn may have up to 512 user equipments. It is obvious that making a configuration of this kind manually is troublesome. Modifications of certain parameters, e.g., the movement of user equipment from one cell to another cell, the variation of the transmission capacity (bandwidth) of a Node B, etc., as may occur in actual practice cannot at all be taken into consideration in the configuration with justifiable effort. Therefore, the methods of the prior art only allow making a limited statement about the function and particularly the load capacity of any RNC.
What is desired therefore is to improve the prior art manual method for configuring a network topology, as well as to create the possibility of carrying out tests that come closer to the real, practical behavior of the network than previously.